Counter propeller for air propeller-driven craft



,R. WAGNER COUNTER PROPELLER FOR AIR PROPELLER DRIVEN IRAFT Dec. 7 1926.

2 Sheets-Sheet 1 INVENTOR ORNEYS Filed June. 16, 1926 Dec. 7 1926.

R. WAGNER v I COUNTER PROPELLER FOR AIR PROPELLER DRIVEN CRAFT Filed June 16, 1926 2 Sheets-Sheet 2 INVENTOR 7 BY 2 r 3 Q JA ORNEYS Patented Dec. 7, 1926.

UNITED STATES BUDOLI' WAGNER, OF HAMBURG, GERMANY.

COUNTER PROPELLER FOR AIRPROPELLEB-DBIVEN CRAFT.

Application filed June 16, 1926, Serial No. 116,377, and in Germany April 10, 1926.

i and relating to fixed counter propellers for increasing the screw propeller efiiciency.

Counter propellers in their general principle and application are known in the art, for instance as represented by the U. S. Patent- No. 1,461,841 granted, to me on July 17, 1923. In this patent I have reduced to practice the idea involved in counter propellers for ship in which the conditions for structurally attaching the counter propellers are particularly favorable in so far as a ship, owing to its shape has ready available rigid portions near the screw propeller, such as the rudder post or similar elements, to which thecounter propeller -may easily be attached. Conditions'in air propeller driven craft, such as airplanes, dirigible balloons or the like are quite different in this respect, no portions of the craft being ordinarily located near enough to the screw propeller to attach to them a counter propeller.

The particular object of my invention is an especially advantageous simple and rigid junction between the counter propeller and craft of the last mentioned character." B this special arrangement the counter prope ler can be utilized in certain cases not only for its primary functions, such as are described in my above mentioned patent, but also for structurally stabilizing the craft and for forming the steering apparatus vertically as well as horizontally.

In comparison with a known arrangement of air-counter-propellers, wherein the counter propeller is supported on an extension of the propeller shaft, the present inventionofiers an essential advantage, in so far as the counter propeller is carried by special junct1on elements connected with the craft, for

' instance arms or brackets, embracing the screw propeller in a bow-like fashion. By

this construction the bearings of the screw propeller shaft are not unfavorably influenced by forces acting possibl laterally upon the counter propeller or by its weight, as is the case with the arrangement mentioned before. Furthermore the useful forward thrust of the counter propeller is transmitted in the present case directly to the craftand acts not as an additional force upon the thrust bearing of the propeller shaft. Besides, the screw propeller can be; detached in my novel construction withoutremoving the counter propeller.-

In order to enable the invention to be readily understood reference is made to the accompanying drawings, in which:

Figure 1 is a side elevation of an airship-car (gondola) with a counter propeller;

Figure 2 is a rear end elevation of the same;

Figure 3 is a cross section of the counter propeller taken on the line A -B of Figure 1;-

Figure 4. is a side elevation of the essential portions of a modification;

Figure 5 is a cross section taken on the line A'-Bf of Figure 4;

Figure 6 is a side elevation of a land airplane with counter propeller;

Figure 7 is a rear'end elevation of the same;

Figure 8 is a cross section of the counter propeller taken on the line CD of Figure 6; c

Figure 9 is a top view of a seaplane with counter propeller and Figure 10 is a rear end elevation of the same.

Referring to Figures 1 to 3, 1 designates the body of the car (gondola), 2 a motor, 3 the screw propeller and 4 the stationary counter propeller which in this example is assumed to have four blades arranged crosswise, and which is carried bythree arms embracing in a bow-like fashion the screw propeller 3. These arms are composed in this example each of an outer arm portion 5 and a base portion 6, both parts being naturally. not exactly limited as to their lengths but passing gradually over into each other. The two lateral arms 5 carry the two horizontal blades and the upper arm 5 carries the upper vertical blade of the counter propeller 4:, and thereby these arms 5, 6 carry its weight and transmit the torque and the useful thrust acting on the counter propeller directly to the body 1. According to Figure 3 (longitudinal section A-B), the brackets 6 preferably have a .streamline section symmetrical to the center peller is isposed form a continuation of the stationary part of the vertical blades of the counter propeller.

A further modification, concerning the section of the brackets 6, is exemplified in Figure 5. In this case the section may be also bladelike shaped in order to produce in a known manner a pre-twist of the propeller stream opposite to the rotation of the screw propeller 3.

In Figures 6 to 8, illustrating by way of example the invention for a land airplane, 8 designates the wing of the plane, 9 the pilots seat, 10 a cabin for passengers, 11 a motor, 12 the radiator and 13 the screw propeller, arranged in this example at the rear as a ush pro eller. The counter-pro- Eehind the screw propeller 13 and, as in Figure 1; is provided with two blades 14, 15 crosswise placed to produce a four armed counter propeller, the vertical blades 14 being also used as vertical rudder, because of the entire counter propeller being arranged so that it can swing about the vertical axle 16. In this case, however, it is assumed, that the horizontal blades 15 of the counter propeller are rigidly connected to the blades 14, and that a separate horizontal rudder 17 is provided. The whole movable counter propeller 14, 15 is carried by the arms or brackets 18, 18 embracing the screw propeller 13 in a bowlike manner, the upper arm 18 passing forward on to the motor covering 19 and the lower arm 18' forming a gradual junction with the cabin body 10. The axle 16 in this example represents also a mutual stiffening of the arms 18 and 18'.

In Figures 9 and 10, illustratin a seaplane with two floats, 8 designates t e wing of the plane, 20 the car body for the passengers and the ilot, 21 a motor, 22 the screw propeller and 23, 23,.the counter propeller, which alsoin this example is disposed behind the push screw propeller 22 and fitted with four crosswise placed arms. The counter propeller is carried by two streamline formed brackets 24 connected to the wing 8, which brackets together with the horizontal fixed. art 23 of the counter propeller embrace ow like fashion the screw propeller 22. Brackets 24 may extend downwards to form the rear supporting. bases 25 for the floats 26. In this case too, the counter pro= peller 23, 23 takes part in forming the steering apparatus inasmuch as the horizontal rudder 27 is attached to its horizontal blades 23 and the vertical rudder 28 to its vertical blades 23'. The rudder portions lying in the propeller stream, like in the ex-.

ample Figure 5, may be shaped so as.to form a continuation of the stationary part of the counter propeller blades and thereby assist in straightening out the twisted screw propeller stream.

From the two examples of airplanes according to Figs. 6 ms and Figs. 9 to 10 it is apparent that the present invention shows a further advantage beyond those stated above, to wit that in comparison with existing types of airplanes the fuselage of the air craft can be considerably shortened, without diminishing its stability. Hereby also the lateral turning of the airplane is facilitated. l

I do not desire to limit myself to the precise constructions and arrangements herein shown and described, as it is evident, that modifications may be made therein, as for instance by using the invention also for counter propellers combined with pull propellers disposed at the front of the vehicles, or for counter propellers arranged in front of the screw propeller, or with multiple propeller airplanes, or for other air propeller driven craft, for example for water or land craft or the like, without departing from the spirit of my invention. Furthermore also arrangements are included in my invention, in which the supporting elements for carrying the counter propeller are partially formed by parts of the craft itself.

I claim 1. In air propeller driven. craft having counter propeller in combination with an air screw propeller, the improvement comprising supporting elements on said craft for carrying said counter propeller, said elements embracing the screw propeller in bowlike fashion.

2. In air propeller driven craft having a counter propeller in combination with an air screw propeller, the improvement comprising supporting elements on said craft for carrying said counter propeller, said elements embracing the screw propeller in bowlike fashion, at least a portlonof said counter propeller being movably mounted between said supporting elements.

3. In air propeller driven craft having a counter propeller in combination with an air screw propeller, the improvement comprising supporting elements on said craft for carrying said counter propeller, said ele'- ments embracing the screw propeller in bowlike fashion, one portion of the counter pro- 

